French President Francois Hollande said on Thursday he had reached out to leaders of countries across Africa's Sahel region to work towards freeing French hostages kidnapped by Al-Qaeda's north African branch.

Speaking on the sidelines of the inauguration of Mali's President Ibrahim Boubacar Keita in Bamako, Hollande told reporters he had spent the day in talks with heads of state to "allow us to have the best means of communication, the best contacts, to recover our compatriots."

Al-Qaeda in the Islamic Maghreb released a video on Monday purporting to show seven Westerners it kidnapped in west Africa, footage France's foreign ministry deemed "credible."

The hostages are four Frenchmen kidnapped from a uranium compound in northern Niger three years ago along with a Dutchman, a Swede and a South African who were abducted from Timbuktu in northern Mali in November 2011.

"I will not say more because I have always had as a guideline not to say anything and make sure to get the (desired) result," Hollande said, without revealing the names of the leaders with whom he had spoken.

In the hostage video, released to the Mauritanian news agency ANI, Frenchman Daniel Larribe introduces himself as the head of the French group and says he was kidnapped by Al-Qaeda in the Islamic Maghreb (AQIM).

ANI reported on its website that he was speaking on June 27 and said he was in good health.

The eight minutes and 42 seconds of footage includes statements from Arribe's compatriots Pierre Legrand, Thierry Dol and Marc Feret as well as South African Stephen Malcolm, Dutchman Sjaak Rijke and Swede Johan Gustafsson.

AQIM is currently thought to be holding eight Europeans hostage, including five French nationals.

Hollande said in July that France was "doing everything" to bring the hostages back but "will not talk so as not to complicate a situation which is bad enough."

AQIM grew out of a movement launched in the late 1990s by radical Algerian Islamists who sought the overthrow of the Algerian government to be replaced with Islamic rule.

The organisation linked to Al-Qaeda in 2006 and has spun a tight network across tribes, clans, family and business lines that stretches across the vast Sahel region abutting the southern Sahara desert.